Viewing Available Iface Configurations - Red Hat ENTERPRISE LINUX 5.5 - ONLINE STORAGE GUIDE Manual

11.1. Viewing Available iface Configurations

Red Hat Enterprise Linux 5.5 supports iSCSI offload and interface binding for the following iSCSI
initiator implementations:
• Software iSCSI — like the scsi_tcp and ib_iser modules, this stack allocates an iSCSI host
instance (i.e. scsi_host) per session, with a single connection per session. As a result, /sys/
class_scsi_host and /proc/scsi will report a scsi_host for each connection/session you
are logged into.
• Offload iSCSI — like the Chelsio cxgb3i, Broadcom bnx2i and ServerEngines be2iscsi
modules, this stack allocates a scsi_host for each PCI device. As such, each port on a host bus
adapter will show up as a different PCI device, with a different scsi_host per HBA port.
To manage both types of initiator implementations, iscsiadm uses the iface structure. With this
structure, an iface configuration must be entered in /var/lib/iscsi/ifaces for each HBA port,
software iSCSI, or network device (ethX) used to bind sessions.
To view available iface configurations, run iscsiadm -m iface. This will display iface
information in the following format:
iface_name transport_name,hardware_address,ip_address,net_ifacename,initiator_name
Refer to the following table for an explanation of each value/setting.
Setting
iface_name
transport_name
hardware_address
ip_address
net_iface_name
initiator_name
Table 2. iface Settings
The following is a sample output of the iscsiadm -m iface command:
iface0 qla4xxx,00:c0:dd:08:63:e8,20.15.0.7,default,iqn.2005-06.com.redhat:madmax
iface1 qla4xxx,00:c0:dd:08:63:ea,20.15.0.9,default,iqn.2005-06.com.redhat:madmax
For software iSCSI, each iface configuration must have a unique name (with less than 65
characters). The iface_name for network devices that support offloading appears in the format
transport_name.hardware_name.
For example, the sample output of iscsiadm -m iface on a system using a Chelsio network card
might appear as:
default tcp,<empty>,<empty>,<empty>,<empty>
Viewing Available iface Configurations
Description
iface configuration name.
Name of driver
MAC address
IP address to use for this port
Name used for the vlan or alias binding of a
software iSCSI session. For iSCSI offloads,
net_iface_name will be <empty> because this
value is not persistent accross reboots.
This setting is used to override a default name
for the initiator, which is defined in /etc/
iscsi/initiatorname.iscsi
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